1. بسم الله الرحمن الرحيم

2. Oral Mucous Membrane

3. Objectives:
At the end of this subject students should know thoroughly:
1- The definition & function of oral mucous membrane.
2- The classification of oral mucous membrane.
3- The histological structure of the mucous membrane.
4- The differences between the two different types of the oral epithelium.
5- Keratinocytes and non keratinocytes.
6- The macro & micro-anatomy of the gingival.
7- The macro & micro-anatomy of the hard palate.
8- The different types of lining mucosa.
9- The specialized mucosa and the different types of the papillae.
10- Dento-gingival junction (Histology and Histogenesis)

4. Oral mucous membrane Hard palate Dorsal surface of the tongue
Cheek mucosa
Floor of mouth
Gingiva
Ventral surface of the tongue
Vestibular fornix
Alveolar mucosa
Labial mucosa

5. Masticatory Mucosa

6. Macro-anatomy of the gingiva

7. 1-Free gingiva (Marginal G.)
- It Extends along the cervical level facially and lingually.
- It is freely movable.
-It tapers to knife edge (the gingival margin).
-The free gingiva is about mm. & separated from the attached gingiva by a free gingival groove both labially and lingually.

8. -This groove appears histologically as a v-shaped notch corresponding to a heavy epithelial rete pegs found between the free and attached gingiva.
-This V-shape due to functional forces upon the free gingiva, folding the movable free part upon the immovable attached gingiva.
free
rete pegs
attached gingiva

9. - Shallow groove lined by non-k. epith.
Gingival sulcus
- Shallow groove lined by non-k. epith.
- Its depth varies from zero-6 mm, and the average 1.8 mm.
The more shallow the sulcus
no food impaction
More favorable the condition of the gingival Margin.
- Lymphocytes and plasma cells are commonly seen in the C.T. of the sulcus as a defense reaction.
مهم

10. 2- Attached gingiva
- Immovable, anchored to the underlying cementum or periosteum.
- Mucogingival junction separates it from alveolar mucosa.
- Its surface shows stippling which is due to functional adaptation to mechanical impacts.
- Absence of the stippling denoting inflammation.

11. 3-Interdental papilla and gingival Col
- Fills the interproximal spaces below the contact areas of the teeth.
-If there is no contact point present, it is reduced. e.g. (diastema).(gap bet. 2 teeth).
- Simulates a tent shape. Its apex tapers to the contact area.
- The Interdental gingival tissue found in the depression between the two peaks of the inter d. pap. is called (Col) and it is non-Keratinized.
Gingival col
peak
peak
NON=KERATINIZED:
G.SULCUS….FREE GINIGIVA
G. COL….INTERD.PAPILLA

12. Histology of gingiva مهم No submucosa
Stratified squamous keratenized epithelium
Tall
Epithelial rete peg
Numerous
C.T papilla
Slender
Lamina propria
Irregular
No submucosa

13. TYPES OF KERATINS :
1- Orthokeratinized epith ( 15 %):
The nuclei and the other organelles are completely absent.
2- Parakeratinized epith ( 75 % ):
The nuclei are retained in the whole surface layer and the Keratohyaline granules disappears (SOME ORGANELLS PRESENT).
3- Non Keratinized epith ( 10 % ):
The stratum cornium is absent (located at gingival col and gingival sulcus ).

14. Gingival fibers Circular group Dento-gingival group
Alveolo-gingival group
Dento-periosteal group

15. Macroanatomy of palate
Incisive papilla
Palatine gingiva
Rugae area
Antro-lateral area (fatty zone)
Postro-lateral area (glandular zone)
Median palatine raphe
Soft palate
Uvula

16. Histology of hard palate
Epithelial rete pegs are short , numerous& BOX SHAPED.
Mucosa
ANTROLATERAL(Fatty zone).
POSTERO LATERAL
(Glandular zone)
Submucosa

17. FUNCTION: 1) ANTROLATERAL (FATTY ZONE):
ACT AS CUSION SO PREVENT BONE RESORBTION.
2) POSTEROLATERAL(GLANDULAR ZONE):
CUSION +
PRODUCE MUCOUS SECRETION LUBRICATE FOR SWALLOW.
(NB) SUBMUCOSA IS ONLY PRESENT IN 1) ANT. LAT.
2) POST. LAT

18. DIFFERENTIATE BET. GINGIVA AND HARDPALAT:
PRESENT
ABSCENT
1) SUBMUCOSA
2) RETE PEGS
NUMEROUS
SHORT
BOX SHAPED
NUMEROUS
TALL
ARREGULAR
SELENDER

19. Lining Mucosa

20. Short and few Firmly attached 1- Soft Palate. 2- Lip. 3- Cheek.
4- Inferior (VENTRAL) surface of the tongue
Short and few
Short and numerous

21. HEALTHY LINE INBETWEEN. NASAL SIDE LINED WITH PS. STR. COL. CILIATED
Soft Palate:
ORAL SIDE
NASAL SIDE
Lip
MUCOUS SIDE
LIP
VERMELION BORDER
SKIN SIDE
EPITH.
epithelium is continuous with that of the hard palate but non-keratinized &
HEALTHY LINE INBETWEEN.
NASAL
SIDE
LINED
WITH
PS. STR.
COL.
CILIATED
EPITH
GOBLT
CELLS
THIN
&
NON -KERATINIZED
KERATINIZED
str.squa.epith.
STRATUM LUCIDUIM BET
ST. SPINOSUM & ST.
CORNIUM.
PRODUCE
OILY SUBSTANCE (ELIDINE)
IMP: مهم
PREVENT WATER EVAPORATION IN HOT WEATHER
COOLING SKIN
LAMINA
PROPRIA
THIN + FEW & SHORT PAPILLAE SEPARATED FROM SUBMUCOSA BY CONTINUOS LAYER OF ELSATIC FIBERS
C.T. papillae are numerous and long these deep papillae carry large capillary loops, so the thin layer of epithelium
permits the red color of blood.
(L.CAP LOOP + THIN KERATIN EPITH = RED COLOUR LIPS)
A)ELIDINE :
ARISE FROM LIQUIFACTION OF KERATO HYALINE GRANULES
B) APENDAGES:
1) HAIR FOLLICLE
2) SWEAT GL.
3) SEBACIOUS GL.
RETE
PEGS
FEW
SHORT
SUB -
MUCOSA
FAT CELLS &
(PURE MUCOUS SAL.GL)
FAT CELLS
& LABIAL GL. (PURE MUCOUS)

22. CHEEK MUCOSA
INFERIOR( VENTRAL) SURFACE OF TONGUE
EPITH.
THICK
& NON KERATINIZED
THIN
&NON KERATINIZED
LAMINA
PROPRIA
RETE PEGS
SHORT & FEW
SHORT & NUMEROUS
SUB –
MUCOSA
BUCCAL GL. (MIXED) PREDOMINANTLY MUCOUS
NOT CLEAR (BLEND WITH TONGUE MUSCLES)

23. Soft palate
Nasal side
Oral side

24. - Its epithelium is continuous with that of the hard palate but non-keratinized So between them there is a healthy line

25. Oral side Histology of the soft palate
Lamina propria is thin with few and short papillae.
- A continuous layer of elastic fibers separating lamina propria from submucosa.
- The submucosa contains fat cells and mucous glands.

26. Nasal side
The nasal side is covered with pseudo-stratified columnar ciliated epithelium with goblet cells.

27. Lip

28. Lip
Mucous side
Vermilion border
Skin side

29. Covered by stratified squamous epithelium with thin layer of keratin.
Vermilion border
Covered by stratified squamous epithelium with thin layer of keratin.
C.T. papillae are numerous and long these deep papillae carry large cappillary loops, so the thin layer of epithelium permits the red color of blood.

30. Skin A)Stratum luciduim
WITH ELIDIN OIL
The cells permeated with elaidin (oil) which arise from the liquefaction of keratohyaline granules.

31. B)Skin appendages
Hair follicle
Sebaceous gland .
Sweat glands

32. Nonkeratenized epithelium
Cheek mucosa
Mixed salivary gland
Nonkeratenized epithelium

33. 1- Inferior surface of the tongue.
- Covered by thin non-keratinized epithelium with short & numerous C.T. papillae.
- The submucosa can not be differentiated as a separate layer where it connects the mucous membrane to the C.T. surrounding tongue muscles.

34. Loosely attached
1- Alveolar mucosa.
2- Vestibular fornix .
3- Floor of the mouth.

35. ثاني Floor of the mouth Vestibular fornix Alveolar Mucosa. -The same.
- Adipose T. in the submucosa.
The sublingual and submandibular ducts are present near the covering mucosa in the sublingual folds.
-Loosely connected to underlying structures to permit the movements of lips, cheeks. - Labial frenums (Median and lateral) are folds of M.M. contain loose C.T. with no muscle f.
St. sq. non-k. epith.
Short few C.T. papillae.
- Fiber bundle of L. prop. are thin and regularly interwoven.
-Definite submucosa, may contain small mixed S.G Numerous elastic fib. (thin) in L. prop., (Thick) in submucosa.
ثاني

36. Specialized mucosa
Posterior 1/3
Anterior 2/3

37. Sulcus terminalis Lymphatic portion (pharyngeal part)
Posterior 1/3
Lymphatic portion
(pharyngeal part)
Sulcus terminalis
Anterior 2/3
Papillary portion

38. Tongue papillae 1- Filliform pap. 2- Fungiform pap.
Taste bud
3- Circumvallate pap.
4- Folliate pap.

39. TASTE BUDSمهم SITE: 1)ALL TONGUE PAPILLAE EXCEPT FILLIFORM
TASTE BUDSمهم SITE: 1)ALL TONGUE PAPILLAE EXCEPT FILLIFORM. 2)SOFT PALAT. 3)POSTERIOR PART EPIGLOTTIS.

40. A. The Filiform Papillae
- Found over the entire dorsal surface.
- High narrow, conical structures arranged in rows.
- Composed of central C. T. core covered by keratinized epithelium.
- The primary papilla (C.T. core) send much smaller 1-2 secondary papillae of C.T. toward the surface.
-The epithelium gives projections (threads like) of keratin.
- No taste buds.

41. B. The fungiform papillae
- Project like little mushroom, mm in height.
-Narrow base and smooth rounded tops. Red colour.
- Scattered between filiform
More numerous at the tip of
the tongue than elsewhere.
Each has a central core of primary
C.T. papilla which is covered by thin non-keratinized epithelium.

42. -The secondary papillae of lamina propria bring capillaries very close to the surface epithelium which is also relatively translucent, permitting the blood red colour to appear.
- Contain taste buds, usually one at the top corner.
- The fungiform papillae which is present at the tip of the tongue are responsible for sweet sensation while those on the lateral borders are responsible for salty sensation.
Sweet and salty taste are mediated by
the chorda tympani.
Secondary papillae

43. C. Circumvallate papilla
Trough
(FURROW)

44. - 7-12 in front of the sulcus terminals.
mm in width and height.
- Embedded in the tongue and surrounded by deep trough, so that its upper surface are not much higher than the general level of the M. M. of the tongue.
- Each has central primary papilla of lamina propria, sending secondary papillae to the st. non-k. epith which covers the whole papilla.
- It has a narrow base wide top surface.
- Numerous taste buds are present in the lateral aspects of the papilla facing the trough of the papilla.
- Von-Ebner serou S.G. open in this cleft at the bottom for cleaning and dissolving the trapped food.
- The papilla is responsible for bitter sensation which is mediated by the glossopharyngeal nerve.

45. D. Foliate Papilla.
- 2 in number present on the lateral border at the boundary of the ant 2/3.
- Composed of several leaves(FOLIATE) of varying length arranged vertically.
- It is surrounded by furrows in which Von-Ebner Glands open in it.
- Numerous taste buds present on the lateral walls.
- Covered by St. non-k, epith.
Responsible for sour sensation
which is also mediated by
glossopharyngeal N.

46. Taste bud Taste pore 1- Outer supporting cell 2- Inner supporting cell
3- Neuroepithelial cell

47. Taste sensation
Bitter
Sour
Salt
Sweet

48. Lingual tonsil (lingual follicle)
Weber salivary gland
The lingual follicle is covered by st. sq. non-kerat. epith. overlying a lymphatic tissue and in many sites extend down into it to from wells or pits called lingual crypts.

49. Dento-gingival junction

50. 1ry D.G.J (from Reduced E. E.)
Histogenesis of Dento-gingival junction 1 2
Desmolytic enzymes
Epithelial plug 4
1ry D.G.J (from Reduced E. E.) 3
2nd D.G.J. (from oral E.)

51. LYSIS OF SURROUNDING C.T
Histogenesis of Dento-gingival junction
ORAL EPITH 1
REE 2
Desmolytic enzymes
Epithelial plug
REE
SECRETE
REDUCED ENAMEL EPITH.
FUNCTION :
LYSIS OF SURROUNDING C.T
THEN
REE + ORAL EPITH
( + = FUSE WITH )

52. 1ry D.G.J (from Reduced E. E.)
Histogenesis of Dento-gingival junction
CENTRAL DEGENERATION
OF EPITH PLUG.
WITH OUT BLEEDING
THEN
ORAL EPITH
REE
1ry D.G.J (from Reduced E. E.) 3
1ry D.G.J :
REE SECRETE 1RY ENAMEL CUTICLE
(ACT AS BASEMENT MEMBRANE LAYER)
ATTACHING REE TO
TOOTH ENAMEL. 4
2nd D.G.J. :
REE REPLACED BY ORAL EPITH.
ORAL EPITH SECRETE
2RY ENAMEL CUTICLE.
[NB]:
1)REE IS AN EMBRYONIC TISSUE.
2)BASAL LAMINA = BASEMENT MEMB.
(ELECT.MICR.) (LIGHT .MICR.)
THEN
2nd D.G.J. (from oral E.)

53. Histology of Dento-gingival junction
Superficial flat cells
Basal cell layer
Hemidesmosomes
External basal lamina
Internal basal lamina
Lamina propria
(C.T)

54. Gingival recession ( Passive eruption)

55. Stages of passive eruption
First stage
Clinical crown
Anatomical crown
Coronal end (E)
G.PAPILLA
Apical end C.E.J.
deciduous teeth : 1 year before shedding permanent teeth: Till years.

56. Persist till 40 years Second stage Clinical crown Anatomical crown
Coronal end (E)
Apical end (C).
Persist till 40 years

57. Transitory stage Third stage Anatomical crown Clinical crown
Coronal end (C.E.J.)
Apical end (C)
Transitory stage

58. Persists till the tooth lost
Fourth stage
Anatomical crown
Clinical crown
Coronal end (C)
Apical end (C)
Persists till the tooth lost

59. Stages of passive eruption

60. Epithelial attachment (mode of attachment).
-The attachment of epithelium to the tooth surface is so strong that an attempt to detach the gingiva from the tooth surface the junctional epithelium will tear rather than peel off from the tooth surface.
-This firm union is achieved by what is called epithelial attachment. Under electron microscope this epithelial attachment was found to be basal lamina material to which the hemidesmosomes are attached. It has a thickness of about 400 Å.

61. Thank You